32 # define USE_DEBUG 1
38 	VERBOSE_STATUS = 1 /* make it zero to save 400 bytes kernel memory */
42 static int enabled = 1;
45 #define MISC_FMT_PRESERVE_ARGV0 (1 << 31)
46 #define MISC_FMT_OPEN_BINARY (1 << 30)
47 #define MISC_FMT_CREDENTIALS (1 << 29)
48 #define MISC_FMT_OPEN_FILE (1 << 28)
72  *  - type:   1 byte
95 		Node *e = list_entry(l, Node, list);  in check_file()  local
100 		if (!test_bit(Enabled, &e->flags))  in check_file()
104 		if (!test_bit(Magic, &e->flags)) {  in check_file()
105 			if (p && !strcmp(e->magic, p + 1))  in check_file()
106 				return e;  in check_file()
111 		s = bprm->buf + e->offset;  in check_file()
112 		if (e->mask) {  in check_file()
113 			for (j = 0; j < e->size; j++)  in check_file()
114 				if ((*s++ ^ e->magic[j]) & e->mask[j])  in check_file()
117 			for (j = 0; j < e->size; j++)  in check_file()
118 				if ((*s++ ^ e->magic[j]))  in check_file()
121 		if (j == e->size)  in check_file()
122 			return e;  in check_file()
135 	int fd_binary = -1;  in load_misc_binary()
190 	/* make argv[1] be the path to the binary */  in load_misc_binary()
191 	retval = copy_strings_kernel(1, &bprm->interp, bprm);  in load_misc_binary()
197 	retval = copy_strings_kernel(1, &fmt->interpreter, bprm);  in load_misc_binary()
271 	s[-1] ='\0';  in scanarg()
275 static char *check_special_flags(char *sfs, Node *e)  in check_special_flags()  argument
278 	int cont = 1;  in check_special_flags()
286 			e->flags |= MISC_FMT_PRESERVE_ARGV0;  in check_special_flags()
291 			e->flags |= MISC_FMT_OPEN_BINARY;  in check_special_flags()
298 			e->flags |= (MISC_FMT_CREDENTIALS |  in check_special_flags()
304 			e->flags |= MISC_FMT_OPEN_FILE;  in check_special_flags()
321 	Node *e;  in create_entry()  local
335 	e = kmalloc(memsize, GFP_KERNEL);  in create_entry()
336 	if (!e)  in create_entry()
339 	p = buf = (char *)e + sizeof(Node);  in create_entry()
341 	memset(e, 0, sizeof(Node));  in create_entry()
353 	e->name = p;  in create_entry()
358 	if (!e->name[0] ||  in create_entry()
359 	    !strcmp(e->name, ".") ||  in create_entry()
360 	    !strcmp(e->name, "..") ||  in create_entry()
361 	    strchr(e->name, '/'))  in create_entry()
364 	pr_debug("register: name: {%s}\n", e->name);  in create_entry()
368 	case 'E':  in create_entry()
369 		pr_debug("register: type: E (extension)\n");  in create_entry()
370 		e->flags = 1 << Enabled;  in create_entry()
374 		e->flags = (1 << Enabled) | (1 << Magic);  in create_entry()
382 	if (test_bit(Magic, &e->flags)) {  in create_entry()
392 			int r = kstrtoint(p, 10, &e->offset);  in create_entry()
393 			if (r != 0 || e->offset < 0)  in create_entry()
399 		pr_debug("register: offset: %#x\n", e->offset);  in create_entry()
402 		e->magic = p;  in create_entry()
406 		if (!e->magic[0])  in create_entry()
411 				DUMP_PREFIX_NONE, e->magic, p - e->magic);  in create_entry()
414 		e->mask = p;  in create_entry()
418 		if (!e->mask[0]) {  in create_entry()
419 			e->mask = NULL;  in create_entry()
424 				DUMP_PREFIX_NONE, e->mask, p - e->mask);  in create_entry()
432 		e->size = string_unescape_inplace(e->magic, UNESCAPE_HEX);  in create_entry()
433 		if (e->mask &&  in create_entry()
434 		    string_unescape_inplace(e->mask, UNESCAPE_HEX) != e->size)  in create_entry()
436 		if (e->size > BINPRM_BUF_SIZE ||  in create_entry()
437 		    BINPRM_BUF_SIZE - e->size < e->offset)  in create_entry()
439 		pr_debug("register: magic/mask length: %i\n", e->size);  in create_entry()
443 				DUMP_PREFIX_NONE, e->magic, e->size);  in create_entry()
445 			if (e->mask) {  in create_entry()
447 				char *masked = kmalloc(e->size, GFP_KERNEL);  in create_entry()
451 					DUMP_PREFIX_NONE, e->mask, e->size);  in create_entry()
454 					for (i = 0; i < e->size; ++i)  in create_entry()
455 						masked[i] = e->magic[i] & e->mask[i];  in create_entry()
458 						DUMP_PREFIX_NONE, masked, e->size);  in create_entry()
465 		/* Handle the 'E' (extension) format. */  in create_entry()
474 		e->magic = p;  in create_entry()
479 		if (!e->magic[0] || strchr(e->magic, '/'))  in create_entry()
481 		pr_debug("register: extension: {%s}\n", e->magic);  in create_entry()
491 	e->interpreter = p;  in create_entry()
496 	if (!e->interpreter[0])  in create_entry()
498 	pr_debug("register: interpreter: {%s}\n", e->interpreter);  in create_entry()
501 	p = check_special_flags(p, e);  in create_entry()
507 	return e;  in create_entry()
513 	kfree(e);  in create_entry()
516 	kfree(e);  in create_entry()
522  * '1' enables, '0' disables and '-1' clears entry/binfmt_misc
534 	if (s[count - 1] == '\n')  in parse_command()
536 	if (count == 1 && s[0] == '0')  in parse_command()
537 		return 1;  in parse_command()
538 	if (count == 1 && s[0] == '1')  in parse_command()
540 	if (count == 2 && s[0] == '-' && s[1] == '1')  in parse_command()
547 static void entry_status(Node *e, char *page)  in entry_status()  argument
552 	if (test_bit(Enabled, &e->flags))  in entry_status()
560 	dp += sprintf(dp, "%s\ninterpreter %s\n", status, e->interpreter);  in entry_status()
564 	if (e->flags & MISC_FMT_PRESERVE_ARGV0)  in entry_status()
566 	if (e->flags & MISC_FMT_OPEN_BINARY)  in entry_status()
568 	if (e->flags & MISC_FMT_CREDENTIALS)  in entry_status()
570 	if (e->flags & MISC_FMT_OPEN_FILE)  in entry_status()
574 	if (!test_bit(Magic, &e->flags)) {  in entry_status()
575 		sprintf(dp, "extension .%s\n", e->magic);  in entry_status()
577 		dp += sprintf(dp, "offset %i\nmagic ", e->offset);  in entry_status()
578 		dp = bin2hex(dp, e->magic, e->size);  in entry_status()
579 		if (e->mask) {  in entry_status()
581 			dp = bin2hex(dp, e->mask, e->size);  in entry_status()
603 	Node *e = inode->i_private;  in bm_evict_inode()  local
605 	if (e && e->flags & MISC_FMT_OPEN_FILE)  in bm_evict_inode()
606 		filp_close(e->interp_file, NULL);  in bm_evict_inode()
609 	kfree(e);  in bm_evict_inode()
612 static void kill_node(Node *e)  in kill_node()  argument
617 	list_del_init(&e->list);  in kill_node()
620 	dentry = e->dentry;  in kill_node()
632 	Node *e = file_inode(file)->i_private;  in bm_entry_read()  local
640 	entry_status(e, page);  in bm_entry_read()
652 	Node *e = file_inode(file)->i_private;  in bm_entry_write()  local
656 	case 1:  in bm_entry_write()
658 		clear_bit(Enabled, &e->flags);  in bm_entry_write()
662 		set_bit(Enabled, &e->flags);  in bm_entry_write()
669 		if (!list_empty(&e->list))  in bm_entry_write()
670 			kill_node(e);  in bm_entry_write()
692 	Node *e;  in bm_register_write()  local
698 	e = create_entry(buffer, count);  in bm_register_write()
700 	if (IS_ERR(e))  in bm_register_write()
701 		return PTR_ERR(e);  in bm_register_write()
704 	dentry = lookup_one_len(e->name, root, strlen(e->name));  in bm_register_write()
726 	if (e->flags & MISC_FMT_OPEN_FILE) {  in bm_register_write()
729 		f = open_exec(e->interpreter);  in bm_register_write()
732 			pr_notice("register: failed to install interpreter file %s\n", e->interpreter);  in bm_register_write()
738 		e->interp_file = f;  in bm_register_write()
741 	e->dentry = dget(dentry);  in bm_register_write()
742 	inode->i_private = e;  in bm_register_write()
747 	list_add(&e->list, &entries);  in bm_register_write()
757 		kfree(e);  in bm_register_write()
785 	case 1:  in bm_status_write()
791 		enabled = 1;  in bm_status_write()